Modifying the shape and color of hair is an important area of modern cosmetics. In this way, the hair's appearance can be adapted both to current fashion trends and to a person's individual wishes. Apart from the desired coloring and shaping performance, these agents should cause the least possible damage to the hair and should preferably even have additional conditioning properties.
Depending on the requirements placed on the dyed color, a person skilled in the art is aware of various coloring systems for providing color-modifying cosmetics, in particular for the skin or keratin-containing fibers such as for example human hair. “Oxidation coloring agents”, as they are known, are used for permanent, high intensity coloring results with corresponding fastness characteristics. Such coloring agents conventionally include oxidation dye precursors, known as “developer components” and “coupler components” which, under the influence of oxidizing agents or atmospheric oxygen, react with one another to form the actual dyes. Two-part coloring agents are accordingly for the most part used, from which the mixtures for use are produced only immediately prior to use from a color modifying preparation and an oxidizing agent preparation. Oxidation coloring agents are distinguished by excellent, long-lasting coloring results.
Lightening agents or blonding agents are also conventionally produced immediately prior to use from a hydrogen peroxide-containing oxidation preparation and a blonding powder and/or an alkalizing preparation.
For the purposes of the present application, oxidation coloring agents, lightening agents and blonding agents for keratinic fibers are referred to as color modifying preparations.
In order to achieve optimum coloring or lightening performance, oxidative color modifying preparations generally require an alkaline pH value, in particular between pH 9.0 and pH 11.5. The period of use for attractive coloring results is furthermore conventionally between 10 and 45 min and conventionally between 15 and 60 min for lightening results.
It is therefore necessary for the ready-to-use color modifying preparations to be formulated and packaged such that the color modifying preparation may, on the one hand, readily be distributed onto the keratinic fibers to be treated, while, on the other hand, remaining in the fibers to be treated during the time of use. It is advantageous to this end for the color modifying preparation to have a specific viscosity which, while permitting application of the agent, also retains the agent at the place of use. On the other hand, for the purpose of using the color modifying preparation, it is desirable for it to be possible to produce the preparation by simply mixing the starting preparations (coloring preparation and oxidizing agent preparation for oxidation coloring agents or oxidizing agent preparation and blonding powder and/or alkalizing preparation for lightening and blonding agents) and furthermore for the preparation to be easy to dispense from the mixing vessel and to apply onto the fibers to be treated.
The viscosity required for this purpose may be established by polymeric thickeners in the ready-to-use color modifying preparation, wherein said thickener may be present both in the coloring preparation or alkalizing preparation or in the oxidizing agent preparation.
In order to enable effective mixing, it is advantageous for the coloring preparation or alkalizing preparation and the oxidizing agent preparation to have good fluidity and for the elevated viscosity of the mixture for use only to be established once the two components have been mixed. One option for achieving this aim is to use polymeric thickeners having thickening properties which vary with pH value. A color modifying preparation usually has an alkaline pH value to stabilize oxidation dye precursors and the oxidizing agent preparation has an acidic pH value to stabilize the oxidizing agent, while the mixture for use is intended to have an alkaline pH value. If the polymeric thickener is present in the acidic oxidizing agent preparation, an anionic polymeric thickener which gives rise to a distinct increase in viscosity at an alkaline pH value is thus preferred.
Homo- or copolymers of acrylic acid or methacrylic acid are particularly suitable as such anionic, polymeric thickeners. Relatively large quantities, conventionally between 2.5 and 5 wt. %, of such polymers are generally required to establish the required viscosity in the mixture for use and thus a correspondingly still higher quantity is required in the oxidizing agent preparation.
Elevated polymer contents, in particular of anionic polymeric thickeners, can, however, lead to problems during the production of the oxidizing agent preparations, since using such high concentrations of thickeners can result in clogging in the production plant and equipment, such as metering pumps and valves, in particular in the event of slight fluctuations in pH value. It is therefore particularly desirable, in addition to ensuring economical use of raw materials, to use agents with a reduced content of polymeric thickeners, providing that the viscosity of the mixture for use is not impaired as a result.
Moreover, good miscibility with coloring, alkalizing and blonding preparations should be ensured.
It is therefore desirable to provide a hydrogen peroxide-containing agent for use in multicomponent color modifying preparations for keratinic fibers, which agent has good miscibility of its sub-components, but has a sufficient viscosity to ensure, on the one hand, that the ready-to-use color modifying preparation can be readily applied and, on the other hand, that it remains where it is intended to act during use and does not run off the fibers. Finally, the agent should be distinguished in that the quantity of polymeric thickener is reduced, such that the above-described problems during production of the agent can be minimized or eliminated.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.